def GetAllCFHTBands(path):
wl_u, tot_u, wl_g, tot_g, wl_r, tot_r, wl_i, tot_i, wl_z, tot_z = GetAllCFHTTransmissions(
path)
# Pysynphot requires to convert wl in a true numpy array
# Pysynphot is not compatile with pandas
wl_u = np.array(wl_u)
wl_g = np.array(wl_g)
wl_r = np.array(wl_r)
wl_i = np.array(wl_i)
wl_z = np.array(wl_z)
tot_u = np.array(tot_u)
tot_g = np.array(tot_g)
tot_r = np.array(tot_r)
tot_i = np.array(tot_i)
tot_z = np.array(tot_z)
bp_u = S.ArrayBandpass(wl_u, tot_u, name='CFHT_U')
bp_g = S.ArrayBandpass(wl_g, tot_g, name='CFHT_G')
bp_r = S.ArrayBandpass(wl_r, tot_r, name='CFHT_R')
bp_i = S.ArrayBandpass(wl_i, tot_i, name='CHFT_I')
bp_z = S.ArrayBandpass(wl_z, tot_z, name='CFHT_Z')
return bp_u, bp_g, bp_r, bp_i, bp_z
def transmission(self, airmass=1.0, wavelength=None):
'''Return the air transmission for a specified airmass.
Parameters
----------
airmass : float or astropy.units.Quantity
Airmass to use (default 1.0). The airmass may also be given as
zenith angle [deg].
wavelength : astropy.units.Quantity
Optional wavelength array. If given, the transmission is rebinned
to this wavelength array, otherwise the unbinned data is returned.
Returns
-------
pysynphot.ArrayBandpass
ArrayBandpass with transmission coefficients at each wavelength
'''
import pysynphot as S
if (isinstance(airmass, u.Quantity)
and airmass.unit.physical_type == 'angle'):
airmass = 1.0 / np.cos(airmass)
res = self.zenith_transmission**airmass
if wavelength is None:
return S.ArrayBandpass(self.wavelength,res,name='sky_emission')
else:
res = rebin_1d_trans_box(res, self.wavelength, wavelength)
return S.ArrayBandpass(wavelength,res,name='sky_emission')
def setUp(self):
self.a = S.ArrayBandpass(wave=N.arange(4000, 5000),
throughput=N.ones(1000))
self.disjoint = S.Box(1000, 100)
self.full = S.ArrayBandpass(wave=N.arange(3000, 6000),
throughput=N.ones(3000))
self.partial = S.ArrayBandpass(wave=N.arange(500, 4500),
throughput=N.ones(4000))
def setUp(self):
self.waveup = N.arange(10000, 10100, 10)
self.wavedown = self.waveup[::-1]
self.T = N.arange(10) + 5
self.Tflip = self.T.copy()[::-1]
self.up = S.ArrayBandpass(wave=self.waveup, throughput=self.T)
self.down = S.ArrayBandpass(wave=self.wavedown,
throughput=self.T[::-1])
def _get_bandpass(self, wave):
"""
Get JWST instrument, mode, filter from self.bandpass, use that to create a JWSTInstrument instance, and then
query that for throughput vs wavelength. Use pysynphot.ArrayBandpass() to convert the results to
pysynphot-compatible form.
Parameters
----------
wave: 1D np.ndarray
Wavelength vector onto which JWST bandpass is interpolated
Returns
-------
bp: pysynphot.SpectralElement
pysynphot bandpass converted to pandeia wavelength units.
"""
keys = get_key_list(self.bandpass, separator=',')
if len(keys) != 3:
msg = "JWST bandpass specification must be of the form <instrument>,<mode>,<filter>"
raise EngineInputError(value=msg)
instrument, mode, filt = keys
config = {}
config['instrument'] = {}
config['instrument']['instrument'] = instrument
config['instrument']['mode'] = mode
config['instrument']['filter'] = filt
inst = InstrumentFactory(config=config)
thruput = inst.get_total_eff(wave)
bp = psyn.ArrayBandpass(wave, thruput, waveunits=pandeia_waveunits)
return bp
def get_ukirt_filt(name):
"""
Define UKIRT filters as pysynphot object
"""
try:
t = Table.read('{0}/ukirt/{1}.dat'.format(filters_dir, name),
format='ascii')
except:
raise ValueError('Could not find ukirt filter {0} in {1}/ukirt'.format(
name, filters_dir))
# Convert wavelengths to angstroms (from microns)
wave = t[t.keys()[0]] * 10000.
trans = t[t.keys()[1]]
# Change any negative numbers to 0
bad = np.where(trans < 0)
trans[bad] = 0
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='ukirt_{0}'.format(name))
return spectrum
def get_2mass_filt(name):
"""
Define the 2mass filters as a pysynphot spectrum object
"""
# Read in filter info
try:
t = Table.read('{0}/2mass/{1}.dat'.format(filters_dir, name),
format='ascii')
except:
raise ValueError(
'Could not find 2MASS filter file {0}/2mass/{1}.dat'.format(
filters_dir, name))
wavelength = t[t.keys()[0]]
transmission = t[t.keys()[1]]
# Convert wavelength to Angstroms
wavelength = wavelength * 10**4
# Make spectrum object
spectrum = pysynphot.ArrayBandpass(wavelength,
transmission,
waveunits='angstrom',
name='2MASS_{0}'.format(name))
return spectrum
def get_vista_filt(name):
"""
Define vista filter as pysynphot spectrum object
"""
# Read in filter info
try:
t = Table.read('{0}/vista/VISTA_Filters_at80K_forETC_{1}.dat'.format(
filters_dir, name),
format='ascii')
except:
raise ValueError(
'Could not find VISTA filter file {0}/vista/VISTA_Filters_at80K_forETC_{1}.dat'
.format(filters_dir, name))
# Wavelength must be in angstroms, transmission in fraction
wave = t['col1'] * 10
trans = t['col2'] * 0.01
# Change any negative numbers to 0, as well as anything shortward
# of 0.4 microns or longward of 2.9 microns
# (no VISTA filter transmissions beyond these boundaries)
bad = np.where((trans < 0) | (wave < 4000) | (wave > 29000))
trans[bad] = 0
# Now we can define the VISTA filter bandpass objects
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='VISTA_{0}'.format(name))
return spectrum
def get_ubv_filt(name):
"""
Define ubv (Johnson-Cousin filters) as pysynphot object
"""
try:
t = Table.read('{0}/ubv/{1}.dat'.format(filters_dir, name),
format='ascii')
except:
raise ValueError('Could not find ubv filter {0} in {1}/ubv'.format(
name, filters_dir))
# Convert wavelength from nm to angstroms
wave = t[t.keys()[0]] * 10.
# Convert transmission to ratio (from percent)
trans = t[t.keys()[1]] / 100.
# Change any negative numbers to 0
bad = np.where(trans < 0)
trans[bad] = 0
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='ubv_{0}'.format(name))
return spectrum
def get_decam_filt(name):
"""
Define DECAM filter as pysynphot object
"""
# Read in filter info
try:
t = Table.read('{0}/decam/DECam_filters.txt'.format(filters_dir),
format='ascii')
t.rename_column('Y', 'y')
cols = np.array(t.keys())
idx = np.where(cols == name)[0][0]
trans = t[cols[idx]]
except:
raise ValueError(
'Could not find DECAM filter {0} in {1}/decam/DECam_filters.txt'.
format(name, filters_dir))
# Limit to unmasked regions only
mask = np.ma.getmask(trans)
good = np.where(mask == False)
# Convert wavelengths from nm to angstroms, while eliminating masked regions
wave = t['wavelength'][good] * 10.
trans = trans[good]
wave = np.ma.filled(wave)
trans = np.ma.filled(trans)
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='decam_{0}'.format(name))
return spectrum
def bandpass(self):
if hasattr(self, "_bp"):
return self._bp
i = self.pandeia_instrument
det_params = i.get_detector_pars()
# 'rn_fudge': multiplied in to match IDT results.
# 'var_fudge': chromatic fudge factor. quantum yield squared.
# 'fullwell':
# 'ff_electrons':
# 'pix_size':
#
wr = i.get_wave_range()
wave = np.linspace(wr['wmin'], wr['wmax'], num=500)
pce = i.get_total_eff(wave)
if pce[0] != 0.:
wave = np.insert(wave, 0, wave[0] - (wave[1] - wave[0]))
pce = np.insert(pce, 0, 0.)
if pce[-1] != 0.:
wave = np.append(wave, wave[-1] + (wave[-1] - wave[-2]))
pce = np.append(pce, 0.)
self._bp = ps.ArrayBandpass(wave=wave,
throughput=pce,
waveunits='micron',
name='bp_{}_{}'.format(
self.instrument, self.filter))
self._bp.convert('angstroms')
return self._bp
def get_PS1_filt(name):
"""
Define PS1 filter as pysynphot object
"""
try:
t = Table.read('{0}/ps1/PS1_filters.txt'.format(filters_dir),
format='ascii')
t.rename_column('col1', 'wave')
t.rename_column('col2', 'open')
t.rename_column('col3', 'g')
t.rename_column('col4', 'r')
t.rename_column('col5', 'i')
t.rename_column('col6', 'z')
t.rename_column('col7', 'y')
cols = np.array(t.keys())
idx = np.where(cols == name)[0][0]
trans = t[cols[idx]]
except:
raise ValueError('Could not find PS1 filter {0} in {1}/ps1'.format(
name, filters_dir))
# Convert wavelengths from nm to angstroms
wave = t['wave'] * 10.
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='ps1_{0}'.format(name))
return spectrum
def get_nirc1_filt(name):
"""
Define Keck/NIRC filters as pysynphot object
"""
try:
t = Table.read('{0}/nirc1/{1}.txt'.format(filters_dir, name), format='ascii')
except:
raise ValueError('Could not find NIRC1 filter {0} in {1}/nirc1'.format(name, filters_dir))
# Convert wavelengths to angstroms
wave = t['col1'] * 10**4
trans = t['col2']
# Lets fix wavelength array for duplicate values or negative vals;
# delete these entries
diff = np.diff(wave)
idx = np.where(diff <= 0)[0]
while(len(idx) != 0):
bad = idx + 1
wave = np.delete(wave, bad)
trans = np.delete(trans, bad)
diff = np.diff(wave)
idx = np.where(diff <= 0)[0]
# Change any negative transmission vals to 0
bad = np.where(trans < 0)
trans[bad] = 0
spectrum = pysynphot.ArrayBandpass(wave, trans, waveunits='angstrom', name='nirc1_{0}'.format(name))
return spectrum
def get_jwst_filt(name):
"""
Define JWST filter as pysynphot object
"""
try:
t = Table.read('{0}/jwst/{1}.txt'.format(filters_dir, name),
format='ascii')
except:
raise ValueError('Could not find JWST filter {0} in {1}/jwst'.format(
name, filters_dir))
# Convert wavelengths to angstroms
wave = t['microns'] * 10**4.
trans = t['throughput']
# Change any negative numbers to 0
bad = np.where(trans < 0)
trans[bad] = 0
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='jwst_{0}'.format(name))
return spectrum
def apply_filter(stars, colour):
"""
Generates a binary filter based on the colour selected and passes the stars
spectrum through this filter, being normalised to its actual magnitude as observed
outputs an oberservation from this spectrum for use in other programs
"""
nwavels = 3501
wavels = np.linspace(3500, 7000, nwavels)
if colour == "red":
throughput = custom_bandpass(wavels, [5750, 6500]) # 750nm range
elif colour == "green":
throughput = custom_bandpass(wavels, [4750, 6000]) # 1250nm range
elif colour == "blue":
throughput = custom_bandpass(wavels, [4000, 5250]) # 1250nm range
band_bin = S.ArrayBandpass(wavels, throughput)
for star in stars:
star_obj = star[0]
mag = star[3]
filtered_spec = star_obj.renorm(mag, 'vegamag', band_bin)
observation = S.Observation(filtered_spec, band_bin, binset=wavels)
star.append(filtered_spec)
star.append(observation)
return stars
def get_naco_filt(name):
"""
Define VLT NACO filters as pysynphot object
"""
try:
t = Table.read('{0}/naco/{1}.dat'.format(filters_dir, name),
format='ascii')
except:
raise ValueError('Could not find NACO filter {0} in {1}/naco'.format(
name, filters_dir))
# Convert wavelengths to angstroms
wave = t['col1'] * 10**4
trans = t['col2']
# Change any negative numbers to 0
bad = np.where(trans < 0)
trans[bad] = 0
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='naco_{0}'.format(name))
return spectrum
def SVO_passband(pb, pbzp=None, List = False):
"""
Read a SVO passband using https://github.com/hover2pi/svo_filters.
Parameters
----------
pb : str
pysynphot obsmode or obsmode listed in `pbzptmag.txt`
pbzp : float, optional
AB magnitude zeropoint of the passband
List : Bool, optional
List all filters available through SVO
Returns
-------
pb : :py:class:`pysynphot.ArrayBandpass` or :py:class:`pysynphot.obsbandpass.ObsModeBandpass`
The passband data.
Has ``dtype=[('wave', '<f8'), ('throughput', '<f8')]``
pbzp : float
passband AB zeropoint - potentially NaN if this was not supplied. If NaN
this can be computed assuming an AB source - i.e. a source with a flux
density of 3631 jy has magnitude = 0 in the bandpass.
Notes
-----
Note that this is a straight read of a single passband from a file. The
zeropoint returned is whatever was provided (even if the value is not
useful) or NaN. To load the passband and get the correct zeropoint, use
:py:func:`source_synphot.passband.load_pbs`
See Also
--------
:py:func:`astropy.table.Table.read`
:py:func:`pysynphot.ObsBandpass`
"""
from svo_filters import svo
from astropy import units as u
if List:
print(list(svo.filters()['Band']))
if pbzp is None:
pbzp = np.nan
try:
pbdata = svo.Filter(pb)
wav = pbdata.wave.to(u.Angstrom).flatten().value
wav, ind = np.unique(wav, return_index=True)
out = S.ArrayBandpass(wav, pbdata.throughput.flatten()[ind], waveunits='Angstrom', name=pb)
except (OSError,IOError) as e:
message = 'No passband called {} in SVO'.format(pb)
out = None
if out is None:
raise ValueError(message)
return out, pbzp
def defarrays(self):
#Supposes that the range variables have already been set
w = N.arange(*self.sprange)
f = N.zeros(w.shape)
f[slice(*(self.spnonzero - w[0]))] += 1.0
self.sp = S.ArraySpectrum(wave=w, flux=f)
w = N.arange(*self.bprange)
t = N.zeros(w.shape)
t[slice(*(self.bpnonzero - w[0]))] += 1
self.bp = S.ArrayBandpass(w, t)
def __call__(self, ebmv, sp=bb):
"""
Returns a pysynphot spectral element instance.
If sp is not specified, use the default wavelength set from the BlackBody
spectrum.
Assume that sp.wave is in angstrom.
"""
t = self.function(sp.wave / 1.e4, ebmv, Alambda=False)
ext = S.ArrayBandpass(wave=sp.wave, throughput=t, waveunits='angstrom')
return ext
def get_gaia_filt(version, name):
"""
Define Gaia filters as pysynphot object
version: specify dr1, dr2, or dr2_rev
name: filter name
"""
# Set the filter directory
if version == 'dr1':
path = '{0}/gaia/dr1/'.format(filters_dir)
elif version == 'dr2':
path = '{0}/gaia/dr2/'.format(filters_dir)
elif version == 'dr2_rev':
path = '{0}/gaia/dr2_rev/'.format(filters_dir)
else:
raise ValueError(
'GAIA filter version {0} not understood. Please use dr1, dr2, or dr2_rev'
.format(version))
# Get the filter info
try:
t = Table.read('{0}/Gaia_passbands.txt'.format(path), format='ascii')
if version == 'dr1':
t.rename_column('BP', 'Gbp')
t.rename_column('RP', 'Grp')
else:
t.rename_column('col1', 'LAMBDA')
t.rename_column('col2', 'G')
t.rename_column('col4', 'Gbp')
t.rename_column('col6', 'Grp')
cols = np.array(t.keys())
idx = np.where(cols == name)[0][0]
trans = t[cols[idx]]
# Change 99 values where filters are undefined into 0, to ensure that
# it doesn't mess up our flux values
bad = np.where(trans > 90)
trans[bad] = 0
except:
raise ValueError('Could not find Gaia filter {0}'.format(name))
# Convert wavelengths to angstroms (from nm)
wave = t['LAMBDA'] * 10
spectrum = pysynphot.ArrayBandpass(wave,
trans,
waveunits='angstrom',
name='gaia_{0}_{1}'.format(
version, name))
return spectrum
def testflip_bp(self):
#create a bandpass with wavelength in descending order
T = self.bp.throughput
self.bp2 = S.ArrayBandpass(wave=self.bp.wave[::-1],
throughput=T[::-1],
waveunits=self.sp.waveunits)
#.throughput calls __call__ calls resample
ref = self.bp.throughput[::-1]
tst = self.bp2.throughput
idxr = N.where(ref != 0)[0]
idxt = N.where(tst != 0)[0]
self.assertEqualNumpy(idxr, idxt)
self.assertApproxNumpy(ref[idxr], tst[idxr])
def monoband(lambda_central, width=100):
"""construct a uniform bandpass @ lambda_central & width"""
# can just use pysynphot.Box...
wlo = lambda_central - width + 1
w0 = lambda_central - width / 2. + 1
w1 = lambda_central + width / 2. + 1
whi = lambda_central + width
waveset = arange(wlo, whi)
fluxset1 = zeros(len(arange(wlo, w0)))
fluxset2 = ones(len(arange(w0, w1)))
fluxset3 = zeros(len(arange(w1, whi)))
fluxset = concatenate([fluxset1, fluxset2, fluxset3])
uni = S.ArrayBandpass(waveset, fluxset)
#uni = uni.compute(waveset)
return uni
def get_keck_osiris_filt(name):
"""
Define keck osiris filters as pysynphot object
"""
try:
t = Table.read('{0}/keck_osiris/{1}.txt'.format(filters_dir, name), format='ascii')
except:
raise ValueError('Could not find keck_osiris filter {0} in {1}/keck_osiris'.format(name, filters_dir))
# Convert wavelengths to angstroms (from nm), percentage throughput to fraction
wave = t['col1'] * 10
trans = t['col2'] / 100.
spectrum = pysynphot.ArrayBandpass(wave, trans, waveunits='angstrom', name='keck_osiris_{0}'.format(name))
return spectrum
def get_ztf_filt(name):
"""
Define ztf filters as pysynphot object
"""
try:
t = Table.read('{0}/ztf/{1}.dat'.format(filters_dir, name),
format='ascii')
except:
raise ValueError('Could not find ztf filter {0} in {1}/ztf'.format(name, filters_dir))
wave = t['Wavelength']
trans = t['Transmission']
spectrum = pysynphot.ArrayBandpass(wave, trans, waveunits='angstrom', name='ztf_{0}'.format(name))
return spectrum
def setUp(self):
#Hand-make an observation with well defined ranges
w = N.arange(1000, 1100, 0.5)
self.sp = S.ArraySpectrum(wave=w,
flux=(w - 1000),
fluxunits='counts',
name='slope1')
#Hand make a box so it has fewer points
self.bp = S.ArrayBandpass(wave=N.array(
[1000, 1009.95, 1010, 1030, 1030.05, 1100]),
throughput=N.array([0, 0, 1, 1, 0, 0]),
name='HandBox')
#self.bp=S.Box(1020,20)
self.obs = S.Observation(self.sp,
self.bp,
binset=N.arange(w[6], w[40]))
def GetAllLSSTBands(path):
wl_u,tot_u,wl_g,tot_g,wl_r,tot_r,wl_i,tot_i,wl_z,tot_z,wl_y4,tot_y4=GetAllLSSTTransmissions(path)
bp_u = S.ArrayBandpass(wl_u*10.,tot_u, name='LSST_U')
bp_g = S.ArrayBandpass(wl_g*10.,tot_g, name='LSST_G')
bp_r = S.ArrayBandpass(wl_r*10,tot_r, name='LSST_R')
bp_i = S.ArrayBandpass(wl_i*10.,tot_i, name='LSST_I')
bp_z = S.ArrayBandpass(wl_z*10.,tot_z, name='LSST_Z')
bp_y4 = S.ArrayBandpass(wl_y4*10,tot_y4, name='LSST_Y4')
return bp_u,bp_g,bp_r,bp_i,bp_z,bp_y4
def make_bandpass(lam_obs, z_em):
lam_ly = [
1216 * (1. + z_em) + 0.01, 1216 * (1. + z_em) - 0.01,
1026 * (1. + z_em) + 0.01, 1026 * (1. + z_em) - 0.01
]
lam_ly += [
973 * (1. + z_em) + 0.01, 973 * (1. + z_em) - 0.01,
950 * (1. + z_em) + 0.01, 950 * (1. + z_em) - 0.01
]
lam_obs = concatenate([lam_obs, lam_ly])
lam_obs = unique1d(lam_obs)
lam_obs = sort(lam_obs)
tau_eff = tau2(lam_obs, z_em) + tau3(lam_obs, z_em) + tau4(
lam_obs, z_em) + tau5(lam_obs, z_em)
#trans = exp(-1.*tau_eff)
trans = where(lam_obs < (912. * (1. + z_em)), 0., exp(-1. * tau_eff))
# set transmitted flux to zero beyond Lyman limit
bp = S.ArrayBandpass(wave=lam_obs, throughput=trans)
return bp
def get_nirc2_filt(name):
"""
Define nirc2 filter as a pysynphot spectrum object
"""
# Read in filter info
try:
t = Table.read('{0}/nirc2/{1}.dat'.format(filters_dir, name),
format='ascii')
except:
raise ValueError(
'Could not find NIRC2 filter file {0}/nirc2/{1}.dat'.format(
filters_dir, name))
wavelength = t[t.keys()[0]]
transmission = t[t.keys()[1]]
# Lets fix wavelength array for duplicate values
diff = np.diff(wavelength)
idx = np.where(diff <= 0)[0]
while len(idx) != 0:
wavelength[idx + 1] += 1.0e-8
diff = np.diff(wavelength)
idx = np.where(diff <= 0)[0]
#print( 'Duplicate entry loop' )
# Get rid of all entries with negative transmission
idx = np.where(transmission > 1)[0]
# Convert wavelength to Angstroms, transmission to ratio
wavelength = wavelength[idx] * 10**4
transmission = transmission[idx] / 100.0 # convert from % to ratio
# Make spectrum object
spectrum = pysynphot.ArrayBandpass(wavelength,
transmission,
waveunits='angstrom',
name='NIRC2_{0}'.format(name))
return spectrum
def create_stellar_obs(aperture, central_obscuration, nwavels, wl_range,
star_dict):
"""
Creates an observation object from pysynphot phoenix models
Parameters:
Aperture (cm): Aperture of the telescope
central_obscuration (cm): diameter of central obscuration of telescope
nwaels: number of wavelengths to sample
wl_range (Angstroms): [first wavelength, last wavelength]
star_dict: dictionary of the following structure
{"mag": float, # vega mag
"Teff": int,
"Z": float,
"log g": float}
Returns:
A pysynphot observation object describing the star being observed through the given telescope architecture
"""
# Set Telescope values
r = (aperture - central_obscuration) / 2
collecting_area = (np.pi * r**2)
S.refs.setref(area=collecting_area) # Takes units of cm^2
wavels = np.linspace(wl_range[0], wl_range[1], nwavels)
throughput = np.ones(nwavels)
bandpass = S.ArrayBandpass(wavels, throughput)
# Create star object
star_obj = S.Icat('phoenix', star_dict["Teff"], star_dict["Z"],
star_dict["log g"])
spec_filt = star_obj.renorm(star_dict["mag"], 'vegamag', bandpass)
# Create observation object
obs = S.Observation(spec_filt, bandpass, binset=wavels)
return obs
def ABmag(spec, bandpass):
if bandpass == None:
bandpass = S.ArrayBandpass(defwaveset, ones(len(defwaveset)))
stflux = 10.**(48.6 / -2.5)
abu = S.ArraySpectrum(defwaveset,
ones(len(defwaveset)) * 10.**(48.6 / -2.5),
fluxunits='fnu')
#abu = spectrum.FlatSpectrum(10.**(48.6/-2.5),fluxunits='fnu')
if bandpass.wave[-1] > spec.wave[-1]:
# if bandpass wavelenth range is longer than spectrum
n = searchsorted(bandpass.wave, spec.wave[-1])
merge = concatenate((spec.wave, bandpass.wave[n:]))
merge = sort(unique(merge))
flux_standard = S.ArraySpectrum(merge,
ones(len(merge)) * stflux,
fluxunits='fnu')
else:
flux_standard = S.ArraySpectrum(spec.wave,
ones(len(spec.wave)) * stflux,
fluxunits='fnu')
# Sets the wavelength array of abu
# print spec.flux.min(),spec.flux.max()
# print spec.flux
# l = format("%10.1f %10.2e",spec.wave,spec.flux)
# print l
# print (spec*bandpass).integrate()
# print (flux_standard*bandpass).integrate()
numerator = (spec * bandpass).integrate()
denominator = (flux_standard * bandpass).integrate()
ratio = numerator / denominator
if ratio <= 0.:
abmag = 999.
else:
abmag = -2.5 * math.log10(ratio)
return abmag
